To share a portion of a YouTube video through ViewPure you first need to paste the URL of your chosen video into the ViewPure "purifier" on the homepage. Then after your video loads you can click on the gear icon below your video to open the options to specify the start and end time of the video that you want to share. That same screen also provides the option to set a password that others must use to view the clipped version of your chosen video. See my screenshots below for more directions.